Disney has already taken the plunge into revisiting its glorious past, as seen in 2016 remakes of The Jungle Book and Pete’s Dragon, but this is on a different scale. Mary Poppins Returns sees the sugar-spooning, supercalafragilisticating, magic floating nanny, now embodied by Emily Blunt, umbrella-parachuting in to rescue a new Thirties generation of Banks children along with the original Michael and Jane, played by Ben ‘Paddington’ Whishaw and paragon of Englishness Emily Mortimer. And if it’s not practically perfect in every way, as Mary P would say, then a lot of people are going to bed without their tea.

Jay Maidment/Disney Enterprises, Inc

That goes for the setting, too, of course. Although PL Travers, the author of the books, lived in London – you can find a blue plaque outside her former home at 50 Smith Street in Chelsea – the 1964 Mary Poppins was filmed entirely in the Walt Disney Studios in Burbank, California. It was as fake as Dick Van Dyke’s Cockney accent but its hyper-real storybook version of London – a blend of period and animation, also seen in the later Bedknobs and Broomsticks – with grand buildings, generous houses and expansive parks, is as distinctive as Dickens’ slum dwellings or Swinging Sixties Carnaby Street. So how does this long-awaited sequel match up?

Well, the 2018 return is likewise largely confected in a studio – this time, Shepperton Studios in Surrey, previously home to films from Alien to Mamma Mia! Here We Go Again, as well as director Rob Marshall’s last film, 2014’s Into The Woods. There is, however, a shift in emphasis – to make this version a little more real while placing it in the same universe.

They created the shorthand term ‘Londony’, according to production designer John Myrhe: ‘I told everyone on my team – all my set designers, and illustrators, and painters – that everything we do from now on needs to be Londony.’ That meant the inclusion of shots of St Paul’s (pictured) and the Tower of London, but also more extended sequences in real locations.

First up was a scene-setting, seasons-changing tour through London’s streets that leads to the Banks home in Cherry Tree Lane. That was at Shepperton, but on the way are many real locations chosen for Victorian period details, including Blossom Street and Fleur de Lis Street in the east of the city.

A larger set piece is the visit to the bank where Michael works, like his kite-flying father before him. For this, they went to the monumental Bank of England itself and the temple-like Royal Exchange (pictured) in the heart of the City, with teams of bowler-hatted extras and a double-decker loaned from the London Bus Museum.

Even more magical, though, was filming in front of Buckingham Palace (pictured). Here, a night shoot captured Mary Poppins sharing a bicycle with Cockney lamplighter Jack (Lin-Manuel Miranda), riding through a proper old London peasouper accompanied by extras on flying cycles and umbrellas.

Elsewhere in the film are new versions of the hybrid sequences we all remember, combining live action with animation, but the production avoided CGI, building sets wherever possible. That meant constructing a fake Big Ben for the climax, created with the help of scouting missions that also took in footage of the real thing. As with the Palace and Bank, it’s all part of creating a London that is, like the Banks’s magical nanny, even better than the real thing. Emily Blunt captures it very neatly: ‘I think of the film as a love letter to London,’ she says.